a) Field of the Invention
The present invention relates to a method of forming a conductive layer of fine pattern to be used as an electrode or wiring of a semiconductor device or the like. More particularly, the invention relates to a method of manufacturing a conductive lamination layer of fine pattern by dry-etching the conductive layer made of refractory metal silicide such as tungsten suicide (WSi.sub.2) at least for an uppermost layer of the conductive lamination layer by using as a mask a TiN or TiON layer containing the direction &lt;200&gt; of Miller indices notation.
b) Description of the Related Art
In a known conventional method of forming a gate electrode layer of fine pattern made of polycide, a polycide layer such as a laminated film (WSi.sub.2 /polysilicon layer) of a WSi.sub.2 film stacked upon a polysilicon layer WSi.sub.2 is dry-etched by using an antireflection layer made of TiN or TiON as a mask (e.g., refer to JP-A-No. 8-17758).
In this specification, "TiON" does not mean that the compositions of "O" and "N" are 1:1, but that it is represented by a general chemical formula "TiO.sub.x N.sub.y " and x and y change with dose amounts of O and N in a TiON layer deposited, for example, by sputtering.
In order to make TiO.sub.x N.sub.y have the function of a conductive film, it is necessary to set the resistance value of TiO.sub.x N.sub.y lower than a predetermined value. To this end, it is preferable that the values x and y satisfy the following conditions.
0.ltoreq.x.ltoreq.0.4
0.8.ltoreq.y1
x/2+y=1
Also in this specification, the compositions of "W" and "Si" of "WSi.sub.2 " are not limited to 1:2, but it is represented by a general chemical formula "W.sub.m Si.sup.n " and m and n change with the compositions of a sputtering target W.sub.m Si.sub.n. W.sub.m Si.sub.n rich in silicon such as WSi.sub.2.7 is often used in practice.